The flat indicator list, optionally filtered by theme / year / search.
Run a data query. Resolves the indicator against the catalogue allowlist, maps
the level to a typ, validates/defaults the year, then builds the SQL from
ONLY those validated pieces. region and fields are applied client-side and
never enter the request.
The 21 subject areas (Themenbereiche), each with its indicator count.
The catalogue is fetched once per query/list call and cached for the lifetime of the client instance, so a
query(which needs the catalogue to resolve the indicator) does not double-fetch.